1. Field of the Invention
This invention relates to a method and system to control an audio/video recording system facilitating transfer of video content from a video source (e.g., an analog or digital video source such as a camcorder, or an equivalent source) to recording media (such as one or more DVDs, or equivalents) with minimal user interaction, and more particularly to methods and systems to control synchronization, buffering, and data recording on recording media in at least one audio/video recording system.
2. Description of the Prior Art
Audio/video recording systems (e.g., CD or DVD recording systems, and equivalents) can be used in many applications, such as for recording video data from home camcorders, television broadcasts, and other sources of video data. Typical tasks in such applications include acquisition and buffering the video data to an intermediate medium (e.g., hard drive, a mass memory medium, or an equivalent medium) and subsequently recording the video data on a recording medium, such as a CD, DVD, flash memory, or an equivalent non-volatile recording medium. Another example is acquisition and direct recording of video data on a recording medium, such as a CD, DVD, flash memory, or an equivalent non-volatile recording medium. Such applications can involve audio and/or video acquisition and recording over cable or other types of networks, or the transmission can be wireless transmissions.
There are existing schemes to control audio/video recording systems, but they require a significant complexity to provide essential functions of audio/video data buffering and recording with acceptable accuracy and reliability of the data on a recording medium, such as a CD, DVD, flash memory, or an equivalent non-volatile recording medium.
One major problem with prior art systems that involve recording of video data to an intermediate medium is the significant time required to complete the task, since it consists of two steps: first, recording video to an intermediate medium that takes as much time as the duration of the video itself (e.g., typically more than two hours for a complete camcorder tape) and second, transferring of the recorded video to a non-volatile medium that varies depending on the data transfer rate of the medium. Another major problem with prior art systems that involve direct recording to a non-volatile medium is the need to synchronize the audio/video data acquisition and recording. In that prior art, the beginning of the recording session typically requires a user to manually synchronize the recording with the beginning of the audio/video data playback or acquisition.
FIG. 1 illustrates a block diagram of a video recording system, in accordance with the prior art. This system would typically reside within a data processing system (e.g., a personal computer, or an equivalent), or have some of the following modules externally connected to the data processing system. A video source 130 acts as a video source to an encoder module 140. Video capture module 150 takes the encoded digital stream (e.g., MPEG-2, or an equivalent) from the encoder module 140 and immediately supplies the encoded stream to a media burner 180 (e.g., a DVD burner or an equivalent module) to record the encoded file on the recording media 190 (e.g., a DVD, a CD, or an equivalent).
The user (not shown) typically activates the media burner module 180 before activating the video source module 130, in order not to lose a portion of the video file initially available that would not be recorded if the media burner module 180 were activated later than the activation of the video source module 130.
Such prior art systems require the user to manually synchronize the acquisition and the recording of video files. The recording media in the media burner needs to “spin up” to start accepting data. Usually in the typical prior art system there is no straightforward way to “spin up” the media other than sending data to the burner module. While media is spinning up the video data is kept in the buffer of the burning module while new data that continues to arrive from Video Capture Module 150 is being added to the buffer. If spinning up of the media takes too long, the Burner Module buffer will overrun and important video file data will be lost in the time it takes the media burner module 180 to actually start recording video files on the recording media 190. This problem can be especially significant when the recording needs to include the earliest available portion of a video file, such as in applications like security camera activation, barely captured audio/video data, and equivalent time-critical situations.
Furthermore, there is another common problem with the acquisition and recording of video files. Even if the media burner module 180 is spun up in time for the video capture module 150 to start outputting video files, if the recording media 190 turns out to be defective or inadequate, then the video file portion recorded on the recording media 190 is typically lost. This can be especially possible when the recording media 190 is low cost and has lower reliability. Important video file data can be lost in the time it takes the user to realize that the recording media 190 is inadequate or defective in storing the video files. The same observations would also apply if the media burner module 180 itself turns out to be defective regardless of the recording media 190 used. Again, this problem can be especially significant when the recording needs to include the earliest available portion of the video file, such as in applications like security camera activation, barely captured audio/video data, and equivalent time-critical situations.
In view of the foregoing, what is needed is an improved method and system to control a video recording system, and permit direct recording of video files acquired from a video source. Various wired and wireless audio/video recording applications could benefit from such methods and systems.